The present invention is directed to the diagnosis of deficits in attention and behavorial inhibition in children, and is more particularly directed to a system for administering objective tests whereby hyperactivity, attention deficit disorders and learning problems can be assessed objectively.
Hyperactivity among children has been a difficult problem to diagnose accurately, and has been primarily determined based on subjective reports by teachers and parents. The objective measurement of hyperactivity has been attempted in the past, but has not been readily available to teachers or to mental health professionals.
Hyperactivity, or more correctly, Attention Deficit Disorder (ADD) with or without hyperactivity, is a rather common problem among children, and conservative estimates place the incidence of hyperactivity at between 3 and 5 percent of the entire national elementary school population. Hyperactivity is by far the most frequent reason for behavorial consultations with child psychologists, child psychiatrists and pediatricians, and has presented a problem of major proportions in the nation's educational system. Despite the enormity of this problem, there is a large factor of confusion in the understanding surrounding the concept of hyperactivity. One reason for this is the paucity of valid, reliable diagnostic methods currently available. Other reasons are confusion over terminology and a tendency, among health professionals, to view hyperactivity primarily based on his or her own personal value system, theoretical orientation, professional training and general philosophical view of child development.
For many years, mechanical tasks such as the Gardner Steadiness Tester have been used for research purposes. However, these have not found popularity among professionals, largely because of the extreme expense involved in constructing a suitable device. For example, a tester for conducting the Continuous Performance Task would cost over $ 8,000 each to build. Consequently, only a few of these devices exist, and these are located in research organizations, but not at clinics.
Various paper-and-pencil tests have been used in the past to diagnose hyperactivity. These include the Porteus mazes, the Matching Familiar Figures test and some sub-tests of the Wechsler Intelligence Scale for Children-Revised (WISC-R). While some of these tests can discriminate between hyperactive and non-hyperactive groups, the tests are also influenced by other factors, such as visual scanning abilities and intelligence or IQ. Consequently, poor performance on a test such as the Matching Familiar Figures test can indicate either hyperactivity, visual motor deficits, perceptual problems, or some combination of these, but cannot adequately distinguish which is the real problem.
Because of the deficiencies in previously-proposed hyperactivity testing schemes, there is a high risk that a child would be misdiagnosed as hyperactive when a poor test performance was due to other problems. Of course, a misdiagnosed child will not receive the proper treatment, and would not be likely to improve.
Other measures of hyperactivity include questionaires filled out by their parents and/or teachers. As such, these tests rely on the assessments of biased or potentially biased persons, and yield subjective estimates of hyperactivity. These are not always based directly on the child's behavior. However, as clinical practitioners become increasingly conservative in their use of medication, and opt more often for cognitive/behavorial intervention, it becomes more and more important for assessment to be based on a child's actual behavior.
Research in the recent past has pointed to a clear relationship behind hyperactivity in a child and his or her impulsivity. Based on this relationship, the Applicant has previously developed an objective measure of impulsivity based on the child's actual behavior. This is referred to as the "Gordon's Measure of Impulsivity" or "GMI", and is described in the Journal of Abnormal Child Psychology, Vol. 7, No. 3, 1979, pgs. 317-326.
The GMI involves a specialized timing device wherein the subject earned reward points by pressing a response button and waiting a prescribed interval of time before hitting the button again. If the child pressed the response button before the interval response time had elapsed, no points were earned, and the timer was reset. However, if the child waited long enough, a response light went on and a point was scored. At the end of a session, the child was given rewards based on the total reward points earned.
Although the GMI has proven to be useful in objective measurement of impulsivity, further research has shown the latter is only one of several factors that can be used in diagnosing hyperactivity.
Another factor which has been found important in diagnosis is the ability of the child to maintain his attention over a span of time. Still another factor is the distractibility of the child, that is, the tendency for outside events to break the child's concentration. Yet another factor is a comparison of the child's responses across modalities (i.e., between visual and auditory).